Tube and fin heat exchanger

ABSTRACT

A tube and fin heat exchanger and method of making in which a tube includes a pair of spaced apart flanges projecting outwardly from one side of the tube and a serpentine fin having coplanar crests on one side of the fin is in contact with the tube side between the flanges and with the opposite edges of the fin located between and against the flanges and the flanges being distorted toward each other thereby comprising means for securing the fin opposite edges to lock the fin in position with the fin crests at the one side of the fin against the tube side preparatory to permanent bonding as by brazing. In the method the fin crests are located against the side of the tube and the opposite flanges on that side are then distorted toward each other to grasp securely the opposite edges of the serpentine fin.

United States Patent [191 Awe et a1.

[ 1 May 8, 1973 [54] TUBE AND FIN HEAT EXCHANGER [73] Assignee: Modine Manufacturing Company,

Racine,Wis.

[22] Filed: May 3, 1971 [21] Appl. No 139,737

UNITED STATES PATENTS Murray, Jr .l65/l82 X Kritzer ..l65/183 FOREIGN PATENTS OR APPLICATIONS 885,072 12/1961 GreatBritain ..l65/183 1,200,681 7/1970 GrcatBritain ..165/183 143,034 9/1949 Australia ..l65/183 Primary Examiner-Charles J. Myhre Assistant Examiner-Theophil W. Streule, Jr. Attorney-Hofgren, Wegner, Allen, Stellman & Mc- Cord [57] ABSTRACT A tube and fin heat exchanger and method of making in which a tube includes a pair of spaced apart flanges projecting outwardly from one side of the tube and a serpentine fin having coplanar crests on one side of the fin is in contact with the tube side between the flanges and with the opposite edges of the fin located between and against the flanges and the flanges being distorted toward each other thereby comprising means for securing the fin opposite edges to lock the fin in position with the fin crests at the one side of the fin against the tube side preparatory to permanent bonding as by brazing. In the method the fin crests are located against the side of the tube and the opposite flanges on that side are then distorted toward each other to grasp securely the opposite edges of the serpentine fin.

5 Claims, 6 Drawing Figures Patented May 8, 1973 3,731,732

. 9 38 Ann/1"" f" (/uvu vvv 3 38 M FIG.6

INVENTORS RUSSELL c. AWE JAMES C. BURTON THOMAS e. BLANK K fifl 1 ma @1144; BY amw ATTORNEYS.

TUBE AND FIN HEAT EXCHANGER SUMMARY OF THE INVENTION One of the features of this invention is to provide an improved tube and fin heat exchanger in which the tube has a pair of spaced apart flanges projecting outwardly from the side of the tube and distorted slightly toward each other to comprise means for securely grasping the opposite coplanar edges of the serpentine fin and retaining the crests on one side of the fin against the side of the tube.

Another feature of the invention is to provide a method of making a tube and fin heat exchanger in which the fin crests on one side of a serpentine fin are positioned against a side of the tube between projecting flanges integral with the tube and these flanges then distorted toward each other to grasp securely the opposite fin edges and hold the fin crests on the one side of the serpentine fin against the side of the tube that is between the flanges.

Other features and advantages of the invention will be apparent from the following description of certain embodiments thereof taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is semi-diagrammatic end elevational view of a heat exchanger embodying the invention and illustrating diagrammatically a method of making the exchanger.

FIG. 2 is a plan view of the fin and tube assembly of the embodiment of FIG. 1.

FIG. 3 is a view similar to FIG. 1 but showing the tube only of a second embodiment.

FIG. 4 is an end elevational view of another tube embodiment similar to FIG. 3.

FIG. 5 is a view similar to FIG. 3 but illustrating the tube of a further embodiment.

FIG. 6 is a fragmentary plan view of a heat exchanger embodying the invention with the tube formed in parallel serpentine reaches after manufacture of the heat exchanger.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the embodiment of FIGS. 1 and 2 the tube 10 is of elongated, generally oval cross section with substantially parallel sides 11 and oppositeedges or ends 12. Each edge 12 of the tube on each side 11 thereof is provided with projecting edge flanges l3 and 14 and rounded projecting portions 27 against the flanges.

Located against each side 11 of the tube 10 is a serpentine fin I5 having one set of crests l6 spaced from the tube 10 and another set of crests 17 positioned against the side 11 of the tube and between the one pair of flanges 13.

In the embodiment of FIGS. 1 and 2 there is also a second serpentine fin 18 having outer crests 19 similar to the crests 16 and also spaced away from the tube 10 and the opposite crests 20 positioned against the other side 11 of the tube and between the opposite pair of flanges 14.

The pair of flanges 13 are distorted toward each other an amount sufficient to grasp securely the opposite fin edges 21 and 22 as illustrated in FIG. 1 to hold the fin crests 17 against the one side 11 of the tube. The other pair of flanges 14 are similarly distorted toward each other to grasp similarly opposite edges 23 and 24 of the other fin 18 and hold its crests 20 securely against the opposite side 11 of the tube. The necessary amount of distorting is often quite small, such as about 0.020 inch.

The two pairs of flanges l3 and 14 when so distorted thereby form an assembly of tube 10 and opposite serpentine fins 15 so that not only can the assembly be made in a continuous manner but the assembly is so securely fixed that it can then be easily handled for further processing such as brazing or other joining of the contacting surfaces together to make an efficient heat exchanger.

FIG. 1 also illustrates diagrammatically a method of making the heat exchanger. When the opposite fins 15 and 18 are assembled between the pair of flanges l3 and 14 and against the sides 11 of the tube the flanges in each pair 13 and 14 are distorted toward each other as by opposite rollers 26 as in a continuous operation to bind the fins between the flanges as described.

The heat exhanger as shown in the embodiment of FIG. 1 is provided with the projecting surface portions 27 adjacent to and outwardly of the flanges l3 and 14 in order to extend beyond the fin edges 21-24 to serve as fin edge protectors or bumpers. These protectors 27 by extending beyond the fin edges permit the tube and fin assembly to be handled as during further processing without damage to the fin edges. This invention is particularly applicable to soft metal tubes and fins such as aluminum, copper or the like and because the metal is soft accidental damage frequently occurs. However, with the bumpers or protective fenders 27 there is much less likelihood of damage.

The embodiments of FIGS. 3, 4 and 5 show different tube cross sectional shapes. The tube 28 in FIG. 3 has top and bottom flanges 25 and rounded projecting tube portions 39. The tube 40 of FIG. 4 has top and bottom flanges 41 and 42. The tube 31 of FIG. 5 has projecting flanges 32 and rounded projecting portions 33. The tubes of FIGS. 1, 3 and 5 are preferred shapes because of the projecting "bumper" portions 27, 39 and 33.

FIG. 6 illustrates how the heat exchanger can be easily formed with the tube 34 of any of the embodiments in parallel serpentine reaches. These reaches 35, 36 and 37 are connected by end bends 38. This illustrates the security with which the flanges hold the fins against the sides of the tube.

Having described our invention as related to the embodiments shown in the accompanying drawings, it is our intention that the invention be not limited by any of the details of description, unless otherwise specified, butrather be construed broadly within its spirit and scope as set out in the appended claims.

We claim:

1. A tube and fin heat exchanger, comprising: a tube having a side and a pair of spaced apart flanges projecting outwardly from said side of the tube; and a serpentine fin strip having opposite edges extending lengthwise of the strip and fin crests extending transversely of the strip between said edges and in contact with said tube side, said flanges being spaced apart a distance to receive said fin strip between said flanges with said edges adjacent said flanges, said flanges being provided two pairs of said flanges and two of said fins on the opposite sides of said tube.

4. The method of making a tube and fin heat exchanger, comprising: providing a tube having a side and a pair of spaced apart flanges projecting outwardly from said side of the tube; positioning a serpentine fin having crests in contact with said tube side between said flanges, said fin having opposite longitudinally extending edges between which said crests transversely extend; and distorting said flanges toward each other transversely of the fin to clamp securely said fin between said opposite edges.

5. The method of claim 4 wherein said method comprises providing a said tube of elongated, generally oval cross section with opposite sides and opposite edges and with two pairs of said flanges on said opposite sides and adjacent said edges, and positioning a said fin on each of said sides between a said pair of flanges. 

1. A tube and fin heat exchanger, comprising: a tube having a side and a pair of spaced apart flanges projecting outwardly from said side of the tube; and a serpentine fin strip having opposite edges extending lengthwise of the strip and fin crests extending transversely of the strip between said edges and in contact with said tube side, said flanges being spaced apart a distance to receive said fin strip between said flanges with said edges adjacent said flanges, said flanges being distorted toward each other and thereby comprising means for securely grasping said fin opposite edges to clamp said strip transversely therebetween and retain said fin crests against said tube side.
 2. The heat exchanger of claim 8 wherein said tube is of elongated, generally oval cross section with said flanges lOcated at a long side of the tube.
 3. The heat exchanger of claim 2 wherein there are provided two pairs of said flanges and two of said fins on the opposite sides of said tube.
 4. The method of making a tube and fin heat exchanger, comprising: providing a tube having a side and a pair of spaced apart flanges projecting outwardly from said side of the tube; positioning a serpentine fin having crests in contact with said tube side between said flanges, said fin having opposite longitudinally extending edges between which said crests transversely extend; and distorting said flanges toward each other transversely of the fin to clamp securely said fin between said opposite edges.
 5. The method of claim 4 wherein said method comprises providing a said tube of elongated, generally oval cross section with opposite sides and opposite edges and with two pairs of said flanges on said opposite sides and adjacent said edges, and positioning a said fin on each of said sides between a said pair of flanges. 